Doesn't it go well? Is it not on the level but a little slanted?
If it's the latter... I had the same problem with my Elmarit 28mm, which has a square lens hood. When it came back from a cleaning, I noticed that the hood seemed misaligned by a very small margin (probably two or three degrees), so I unscrewed the front element and screwed it back on, making sure that the two little stubs that guide the hood were in a NS position. Before putting it back on, I also applied a tiny bit of nail polish on the thread, to secure it in place. Problem solved... without any loss of sharpness or anything.
If your lens front part can be unscrewed, try that approach. Just be very careful.
